single yaml implementation

consolidate to a single yaml implementation,
removing pyyaml

setup.py

@@ -11,7 +11,6 @@ setup(
     packages=find_packages(),
     include_package_data=True,
     install_requires=[
-        'pyyaml==3.*',
         'ruamel.yaml==0.15.*',
         'jinja2',
         'pluggy>0.7<1.0'

tljh/configurer.py

@@ -9,9 +9,9 @@ FIXME: A strong feeling that JSON Schema should be involved somehow.
 """
 
 import os
-import yaml
 
-from tljh.config import CONFIG_FILE
+from .config import CONFIG_FILE
+from .yaml import yaml
 
 # Default configuration for tljh
 # User provided config is merged into this
@@ -59,7 +59,7 @@ def load_config(config_file=CONFIG_FILE):
     """
     if os.path.exists(config_file):
         with open(config_file) as f:
-            config_overrides = yaml.safe_load(f)
+            config_overrides = yaml.load(f)
     else:
         config_overrides = {}
     return _merge_dictionaries(dict(default), config_overrides)

tljh/jupyterhub_config.py

@@ -1,15 +1,15 @@
 """
 JupyterHub config for the littlest jupyterhub.
 """
-import copy
-import os
-import yaml
+
 from glob import glob
+import os
 
 from systemdspawner import SystemdSpawner
 from tljh import configurer, user
 from tljh.config import INSTALL_PREFIX, USER_ENV_PREFIX, CONFIG_DIR
 from tljh.normalize import generate_system_username
+from tljh.yaml import yaml
 
 
 class UserCreatingSpawner(SystemdSpawner):
@@ -54,7 +54,7 @@ c.SystemdSpawner.unit_name_template = 'jupyter-{USERNAME}'
 config_overrides_path = os.path.join(CONFIG_DIR, 'config.yaml')
 if os.path.exists(config_overrides_path):
     with open(config_overrides_path) as f:
-        config_overrides = yaml.safe_load(f)
+        config_overrides = yaml.load(f)
 else:
     config_overrides = {}
 configurer.apply_config(config_overrides, c)